202

Chapter 36. SuperH SH64 Dependent Features

36.2. Syntax

36.2.1. Special Characters

!

is the line comment character.

You can use

;

instead of a newline to separate statements.

Since

$

has no special meaning, you may use it in symbol names.

36.2.2. Register Names

You can use the predefined symbols

r0

through

r63

to refer to the SH64 general registers,

cr0

through

cr63

for control registers,

tr0

through

tr7

for target address registers,

fr0

through

fr63

for

single precision floating point registers,

dr0

through

dr62

(even numbered registers only) for double 

precision floating point registers,

fv0

through

fv60

(multiples of four only) for single precision float 

ing point vectors,

fp0

through

fp62

(even numbered registers only) for single precision floating point

pairs,

mtrx0

through

mtrx48

(multiples of 16 only) for 4x4 matrices of single precision floating point

registers,

pc

for the program counter, and

fpscr

for the floating point status and control register.

You can also refer to the control registers by the mnemonics

sr

,

ssr

,

pssr

,

intevt

,

expevt

,

pexpevt

,

tra

,

spc

,

pspc

,

resvec

,

vbr

,

tea

,

dcr

,

kcr0

,

kcr1

,

ctc

, and

usr

.

36.2.3. Addressing Modes

SH64 operands consist of either a register or immediate value. The immediate value can be a constant

or label reference (or portion of a label reference), as in this example:

movi 4,r2

pt function, tr4

movi (function

16) & 65535,r0

shori function & 65535, r0

ld.l r0,4,r0

Instruction label references can reference labels in either SHmedia or SHcompact. To differentiate

between the two, labels in SHmedia sections will always have the least significant bit set (i.e. they

will be odd), which SHcompact labels will have the least significant bit reset (i.e. they will be even).

If you need to reference the actual address of a label, you can use the

datalabel

modifier, as in this

example:

.long function

.long datalabel function

In that example, the first longword may or may not have the least significant bit set depending on

whether the label is an SHmedia label or an SHcompact label. The second longword will be the actual

address of the label, regardless of what type of label it is.

36.3. SH64 Machine Directives

In addition to the SH directives, the SH64 provides the following directives: